1. Field of the Invention
This invention relates to methods and apparatus for determining the amounts of one or more selected components of a gas sample. More particularly, this invention relates to measurement apparatus capable of providing accurate quantitative results and that does not require detector calibration with known standards.
2. Description of the Prior Art
A wide variety of procedures have been developed over the years for measuring the amount (i.e. weight) of a selected component of a gas sample. One technique that has proven highly successful is gas chromatography, wherein a predetermined quantity of gas sample containing multiple components is passed through a separation column. Such a column, as by means of selective adsorption chracteristics, separates the components of the sample so that they elute sequentially to permit measurement of each component in turn.
Many different detectors have been employed to measure the amount of the components as they elute from the column. A common characteristic of all conventional detectors is that they require calibration in order to achieve accurate quantitative results. Moreover, no available detector is very sensitive to carbon monoxide, a gas often of practical interest in certain process industries. For example, it is desirable to be able to determine rapidly and efficiently both the oxygen and the carbon monoxide content of the stack gas from gas, oil or coal-fired furnaces and boilers.